text: /*
   * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
   *
   * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
   * All Rights Reserved.
   *
   * Author Rickard E. (Rik) Faith <faith@valinux.com>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
   * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  
  #include <linux/debugfs.h>
  #include <linux/fs.h>
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/mount.h>
  #include <linux/slab.h>
  #include <drm/drmP.h>
  #include <drm/drm_core.h>
  #include "drm_legacy.h"
  #include "drm_internal.h"
  
  unsigned int drm_debug = 0;	/* 1 to enable debug output */
  EXPORT_SYMBOL(drm_debug);
  
  bool drm_atomic = 0;
  
  MODULE_AUTHOR(CORE_AUTHOR);
  MODULE_DESCRIPTION(CORE_DESC);
  MODULE_LICENSE("GPL and additional rights");
  MODULE_PARM_DESC(debug, "Enable debug output");
  MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
  MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
  MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
  
  module_param_named(debug, drm_debug, int, 0600);
  
  static DEFINE_SPINLOCK(drm_minor_lock);
  static struct idr drm_minors_idr;
  
  struct class *drm_class;
  static struct dentry *drm_debugfs_root;
  
  void drm_err(const char *format, ...)
  {
  	struct va_format vaf;
  	va_list args;
  
  	va_start(args, format);
  
  	vaf.fmt = format;
  	vaf.va = &args;
  
  	printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
  	       __builtin_return_address(0), &vaf);
  
  	va_end(args);
  }
  EXPORT_SYMBOL(drm_err);
  
  void drm_ut_debug_printk(const char *function_name, const char *format, ...)
  {
  	struct va_format vaf;
  	va_list args;
  
  	va_start(args, format);
  	vaf.fmt = format;
  	vaf.va = &args;
  
  	printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
  
  	va_end(args);
  }
  EXPORT_SYMBOL(drm_ut_debug_printk);
  
  struct drm_master *drm_master_create(struct drm_minor *minor)
  {
  	struct drm_master *master;
  
  	master = kzalloc(sizeof(*master), GFP_KERNEL);
  	if (!master)
  		return NULL;
  
  	kref_init(&master->refcount);
  	spin_lock_init(&master->lock.spinlock);
  	init_waitqueue_head(&master->lock.lock_queue);
  	idr_init(&master->magic_map);
  	master->minor = minor;
  
  	return master;
  }
  
  struct drm_master *drm_master_get(struct drm_master *master)
  {
  	kref_get(&master->refcount);
  	return master;
  }
  EXPORT_SYMBOL(drm_master_get);
  
  static void drm_master_destroy(struct kref *kref)
  {
  	struct drm_master *master = container_of(kref, struct drm_master, refcount);
  	struct drm_device *dev = master->minor->dev;
  	struct drm_map_list *r_list, *list_temp;
  
  	mutex_lock(&dev->struct_mutex);
  	if (dev->driver->master_destroy)
  		dev->driver->master_destroy(dev, master);
  
  	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
  		if (r_list->master == master) {
  			drm_legacy_rmmap_locked(dev, r_list->map);
  			r_list = NULL;
  		}
  	}
  	mutex_unlock(&dev->struct_mutex);
  
  	idr_destroy(&master->magic_map);
  	kfree(master->unique);
  	kfree(master);
  }
  
  void drm_master_put(struct drm_master **master)
  {
  	kref_put(&(*master)->refcount, drm_master_destroy);
  	*master = NULL;
  }
  EXPORT_SYMBOL(drm_master_put);
  
  int drm_setmaster_ioctl(struct drm_device *dev, void *data,
  			struct drm_file *file_priv)
  {
  	int ret = 0;
  
  	mutex_lock(&dev->master_mutex);
  	if (file_priv->is_master)
  		goto out_unlock;
  
  	if (file_priv->minor->master) {
  		ret = -EINVAL;
  		goto out_unlock;
  	}
  
  	if (!file_priv->master) {
  		ret = -EINVAL;
  		goto out_unlock;
  	}
  
  	file_priv->minor->master = drm_master_get(file_priv->master);
  	file_priv->is_master = 1;
  	if (dev->driver->master_set) {
  		ret = dev->driver->master_set(dev, file_priv, false);
  		if (unlikely(ret != 0)) {
  			file_priv->is_master = 0;
  			drm_master_put(&file_priv->minor->master);
  		}
  	}
  
  out_unlock:
  	mutex_unlock(&dev->master_mutex);
  	return ret;
  }
  
  int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
  			 struct drm_file *file_priv)
  {
  	int ret = -EINVAL;
  
  	mutex_lock(&dev->master_mutex);
  	if (!file_priv->is_master)
  		goto out_unlock;
  
  	if (!file_priv->minor->master)
  		goto out_unlock;
  
  	ret = 0;
  	if (dev->driver->master_drop)
  		dev->driver->master_drop(dev, file_priv, false);
  	drm_master_put(&file_priv->minor->master);
  	file_priv->is_master = 0;
  
  out_unlock:
  	mutex_unlock(&dev->master_mutex);
  	return ret;
  }
  
  /*
   * DRM Minors
   * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
   * of them is represented by a drm_minor object. Depending on the capabilities
   * of the device-driver, different interfaces are registered.
   *
   * Minors can be accessed via dev->$minor_name. This pointer is either
   * NULL or a valid drm_minor pointer and stays valid as long as the device is
   * valid. This means, DRM minors have the same life-time as the underlying
   * device. However, this doesn't mean that the minor is active. Minors are
   * registered and unregistered dynamically according to device-state.
   */
  
  static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
  					     unsigned int type)
  {
  	switch (type) {
  	case DRM_MINOR_LEGACY:
  		return &dev->primary;
  	case DRM_MINOR_RENDER:
  		return &dev->render;
  	case DRM_MINOR_CONTROL:
  		return &dev->control;
  	default:
  		return NULL;
  	}
  }
  
  static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
  {
  	struct drm_minor *minor;
  	unsigned long flags;
  	int r;
  
  	minor = kzalloc(sizeof(*minor), GFP_KERNEL);
  	if (!minor)
  		return -ENOMEM;
  
  	minor->type = type;
  	minor->dev = dev;
  
  	idr_preload(GFP_KERNEL);
  	spin_lock_irqsave(&drm_minor_lock, flags);
  	r = idr_alloc(&drm_minors_idr,
  		      NULL,
  		      64 * type,
  		      64 * (type + 1),
  		      GFP_NOWAIT);
  	spin_unlock_irqrestore(&drm_minor_lock, flags);
  	idr_preload_end();
  
  	if (r < 0)
  		goto err_free;
  
  	minor->index = r;
  
  	minor->kdev = drm_sysfs_minor_alloc(minor);
  	if (IS_ERR(minor->kdev)) {
  		r = PTR_ERR(minor->kdev);
  		goto err_index;
  	}
  
  	*drm_minor_get_slot(dev, type) = minor;
  	return 0;
  
  err_index:
  	spin_lock_irqsave(&drm_minor_lock, flags);
  	idr_remove(&drm_minors_idr, minor->index);
  	spin_unlock_irqrestore(&drm_minor_lock, flags);
  err_free:
  	kfree(minor);
  	return r;
  }
  
  static void drm_minor_free(struct drm_device *dev, unsigned int type)
  {
  	struct drm_minor **slot, *minor;
  	unsigned long flags;
  
  	slot = drm_minor_get_slot(dev, type);
  	minor = *slot;
  	if (!minor)
  		return;
  
  	drm_mode_group_destroy(&minor->mode_group);
  	put_device(minor->kdev);
  
  	spin_lock_irqsave(&drm_minor_lock, flags);
  	idr_remove(&drm_minors_idr, minor->index);
  	spin_unlock_irqrestore(&drm_minor_lock, flags);
  
  	kfree(minor);
  	*slot = NULL;
  }
  
  static int drm_minor_register(struct drm_device *dev, unsigned int type)
  {
  	struct drm_minor *minor;
  	unsigned long flags;
  	int ret;
  
  	DRM_DEBUG("\n");
  
  	minor = *drm_minor_get_slot(dev, type);
  	if (!minor)
  		return 0;
  
  	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
  	if (ret) {
  		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
  		return ret;
  	}
  
  	ret = device_add(minor->kdev);
  	if (ret)
  		goto err_debugfs;
  
  	/* replace NULL with @minor so lookups will succeed from now on */
  	spin_lock_irqsave(&drm_minor_lock, flags);
  	idr_replace(&drm_minors_idr, minor, minor->index);
  	spin_unlock_irqrestore(&drm_minor_lock, flags);
  
  	DRM_DEBUG("new minor registered %d\n", minor->index);
  	return 0;
  
  err_debugfs:
  	drm_debugfs_cleanup(minor);
  	return ret;
  }
  
  static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
  {
  	struct drm_minor *minor;
  	unsigned long flags;
  
  	minor = *drm_minor_get_slot(dev, type);
  	if (!minor || !device_is_registered(minor->kdev))
  		return;
  
  	/* replace @minor with NULL so lookups will fail from now on */
  	spin_lock_irqsave(&drm_minor_lock, flags);
  	idr_replace(&drm_minors_idr, NULL, minor->index);
  	spin_unlock_irqrestore(&drm_minor_lock, flags);
  
  	device_del(minor->kdev);
  	dev_set_drvdata(minor->kdev, NULL); /* safety belt */
  	drm_debugfs_cleanup(minor);
  }
  
  /**
   * drm_minor_acquire - Acquire a DRM minor
   * @minor_id: Minor ID of the DRM-minor
   *
   * Looks up the given minor-ID and returns the respective DRM-minor object. The
   * refence-count of the underlying device is increased so you must release this
   * object with drm_minor_release().
   *
   * As long as you hold this minor, it is guaranteed that the object and the
   * minor->dev pointer will stay valid! However, the device may get unplugged and
   * unregistered while you hold the minor.
   *
   * Returns:
   * Pointer to minor-object with increased device-refcount, or PTR_ERR on
   * failure.
   */
  struct drm_minor *drm_minor_acquire(unsigned int minor_id)
  {
  	struct drm_minor *minor;
  	unsigned long flags;
  
  	spin_lock_irqsave(&drm_minor_lock, flags);
  	minor = idr_find(&drm_minors_idr, minor_id);
  	if (minor)
  		drm_dev_ref(minor->dev);
  	spin_unlock_irqrestore(&drm_minor_lock, flags);
  
  	if (!minor) {
  		return ERR_PTR(-ENODEV);
  	} else if (drm_device_is_unplugged(minor->dev)) {
  		drm_dev_unref(minor->dev);
  		return ERR_PTR(-ENODEV);
  	}
  
  	return minor;
  }
  
  /**
   * drm_minor_release - Release DRM minor
   * @minor: Pointer to DRM minor object
   *
   * Release a minor that was previously acquired via drm_minor_acquire().
   */
  void drm_minor_release(struct drm_minor *minor)
  {
  	drm_dev_unref(minor->dev);
  }
  
  /**
   * drm_put_dev - Unregister and release a DRM device
   * @dev: DRM device
   *
   * Called at module unload time or when a PCI device is unplugged.
   *
   * Use of this function is discouraged. It will eventually go away completely.
   * Please use drm_dev_unregister() and drm_dev_unref() explicitly instead.
   *
   * Cleans up all DRM device, calling drm_lastclose().
   */
  void drm_put_dev(struct drm_device *dev)
  {
  	DRM_DEBUG("\n");
  
  	if (!dev) {
  		DRM_ERROR("cleanup called no dev\n");
  		return;
  	}
  
  	drm_dev_unregister(dev);
  	drm_dev_unref(dev);
  }
  EXPORT_SYMBOL(drm_put_dev);
  
  void drm_unplug_dev(struct drm_device *dev)
  {
  	/* for a USB device */
  	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
  	drm_minor_unregister(dev, DRM_MINOR_RENDER);
  	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
  
  	mutex_lock(&drm_global_mutex);
  
  	drm_device_set_unplugged(dev);
  
  	if (dev->open_count == 0) {
  		drm_put_dev(dev);
  	}
  	mutex_unlock(&drm_global_mutex);
  }
  EXPORT_SYMBOL(drm_unplug_dev);
  
  /*
   * DRM internal mount
   * We want to be able to allocate our own "struct address_space" to control
   * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
   * stand-alone address_space objects, so we need an underlying inode. As there
   * is no way to allocate an independent inode easily, we need a fake internal
   * VFS mount-point.
   *
   * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
   * frees it again. You are allowed to use iget() and iput() to get references to
   * the inode. But each drm_fs_inode_new() call must be paired with exactly one
   * drm_fs_inode_free() call (which does not have to be the last iput()).
   * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
   * between multiple inode-users. You could, technically, call
   * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
   * iput(), but this way you'd end up with a new vfsmount for each inode.
   */
  
  static int drm_fs_cnt;
  static struct vfsmount *drm_fs_mnt;
  
  static const struct dentry_operations drm_fs_dops = {
  	.d_dname	= simple_dname,
  };
  
  static const struct super_operations drm_fs_sops = {
  	.statfs		= simple_statfs,
  };
  
  static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
  				   const char *dev_name, void *data)
  {
  	return mount_pseudo(fs_type,
  			    "drm:",
  			    &drm_fs_sops,
  			    &drm_fs_dops,
  			    0x010203ff);
  }
  
  static struct file_system_type drm_fs_type = {
  	.name		= "drm",
  	.owner		= THIS_MODULE,
  	.mount		= drm_fs_mount,
  	.kill_sb	= kill_anon_super,
  };
  
  static struct inode *drm_fs_inode_new(void)
  {
  	struct inode *inode;
  	int r;
  
  	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
  	if (r < 0) {
  		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
  		return ERR_PTR(r);
  	}
  
  	inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
  	if (IS_ERR(inode))
  		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
  
  	return inode;
  }
  
  static void drm_fs_inode_free(struct inode *inode)
  {
  	if (inode) {
  		iput(inode);
  		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
  	}
  }
  
  /**
   * drm_dev_alloc - Allocate new DRM device
   * @driver: DRM driver to allocate device for
   * @parent: Parent device object
   *
   * Allocate and initialize a new DRM device. No device registration is done.
   * Call drm_dev_register() to advertice the device to user space and register it
   * with other core subsystems.
   *
   * The initial ref-count of the object is 1. Use drm_dev_ref() and
   * drm_dev_unref() to take and drop further ref-counts.
   *
   * Note that for purely virtual devices @parent can be NULL.
   *
   * RETURNS:
   * Pointer to new DRM device, or NULL if out of memory.
   */
  struct drm_device *drm_dev_alloc(struct drm_driver *driver,
  				 struct device *parent)
  {
  	struct drm_device *dev;
  	int ret;
  
  	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  	if (!dev)
  		return NULL;
  
  	kref_init(&dev->ref);
  	dev->dev = parent;
  	dev->driver = driver;
  
  	INIT_LIST_HEAD(&dev->filelist);
  	INIT_LIST_HEAD(&dev->ctxlist);
  	INIT_LIST_HEAD(&dev->vmalist);
  	INIT_LIST_HEAD(&dev->maplist);
  	INIT_LIST_HEAD(&dev->vblank_event_list);
  
  	spin_lock_init(&dev->buf_lock);
  	spin_lock_init(&dev->event_lock);
  	mutex_init(&dev->struct_mutex);
  	mutex_init(&dev->ctxlist_mutex);
  	mutex_init(&dev->master_mutex);
  
  	dev->anon_inode = drm_fs_inode_new();
  	if (IS_ERR(dev->anon_inode)) {
  		ret = PTR_ERR(dev->anon_inode);
  		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
  		goto err_free;
  	}
  
  	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
  		ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
  		if (ret)
  			goto err_minors;
  	}
  
  	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
  		ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
  		if (ret)
  			goto err_minors;
  	}
  
  	ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
  	if (ret)
  		goto err_minors;
  
  	if (drm_ht_create(&dev->map_hash, 12))
  		goto err_minors;
  
  	ret = drm_legacy_ctxbitmap_init(dev);
  	if (ret) {
  		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
  		goto err_ht;
  	}
  
  	if (drm_core_check_feature(dev, DRIVER_GEM)) {
  		ret = drm_gem_init(dev);
  		if (ret) {
  			DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
  			goto err_ctxbitmap;
  		}
  	}
  
  	return dev;
  
  err_ctxbitmap:
  	drm_legacy_ctxbitmap_cleanup(dev);
  err_ht:
  	drm_ht_remove(&dev->map_hash);
  err_minors:
  	drm_minor_free(dev, DRM_MINOR_LEGACY);
  	drm_minor_free(dev, DRM_MINOR_RENDER);
  	drm_minor_free(dev, DRM_MINOR_CONTROL);
  	drm_fs_inode_free(dev->anon_inode);
  err_free:
  	mutex_destroy(&dev->master_mutex);
  	kfree(dev);
  	return NULL;
  }
  EXPORT_SYMBOL(drm_dev_alloc);
  
  static void drm_dev_release(struct kref *ref)
  {
  	struct drm_device *dev = container_of(ref, struct drm_device, ref);
  
  	if (drm_core_check_feature(dev, DRIVER_GEM))
  		drm_gem_destroy(dev);
  
  	drm_legacy_ctxbitmap_cleanup(dev);
  	drm_ht_remove(&dev->map_hash);
  	drm_fs_inode_free(dev->anon_inode);
  
  	drm_minor_free(dev, DRM_MINOR_LEGACY);
  	drm_minor_free(dev, DRM_MINOR_RENDER);
  	drm_minor_free(dev, DRM_MINOR_CONTROL);
  
  	mutex_destroy(&dev->master_mutex);
  	kfree(dev->unique);
  	kfree(dev);
  }
  
  /**
   * drm_dev_ref - Take reference of a DRM device
   * @dev: device to take reference of or NULL
   *
   * This increases the ref-count of @dev by one. You *must* already own a
   * reference when calling this. Use drm_dev_unref() to drop this reference
   * again.
   *
   * This function never fails. However, this function does not provide *any*
   * guarantee whether the device is alive or running. It only provides a
   * reference to the object and the memory associated with it.
   */
  void drm_dev_ref(struct drm_device *dev)
  {
  	if (dev)
  		kref_get(&dev->ref);
  }
  EXPORT_SYMBOL(drm_dev_ref);
  
  /**
   * drm_dev_unref - Drop reference of a DRM device
   * @dev: device to drop reference of or NULL
   *
   * This decreases the ref-count of @dev by one. The device is destroyed if the
   * ref-count drops to zero.
   */
  void drm_dev_unref(struct drm_device *dev)
  {
  	if (dev)
  		kref_put(&dev->ref, drm_dev_release);
  }
  EXPORT_SYMBOL(drm_dev_unref);
  
  /**
   * drm_dev_register - Register DRM device
   * @dev: Device to register
   * @flags: Flags passed to the driver's .load() function
   *
   * Register the DRM device @dev with the system, advertise device to user-space
   * and start normal device operation. @dev must be allocated via drm_dev_alloc()
   * previously.
   *
   * Never call this twice on any device!
   *
   * RETURNS:
   * 0 on success, negative error code on failure.
   */
  int drm_dev_register(struct drm_device *dev, unsigned long flags)
  {
  	int ret;
  
  	mutex_lock(&drm_global_mutex);
  
  	ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
  	if (ret)
  		goto err_minors;
  
  	ret = drm_minor_register(dev, DRM_MINOR_RENDER);
  	if (ret)
  		goto err_minors;
  
  	ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
  	if (ret)
  		goto err_minors;
  
  	if (dev->driver->load) {
  		ret = dev->driver->load(dev, flags);
  		if (ret)
  			goto err_minors;
  	}
  
  	/* setup grouping for legacy outputs */
  	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
  		ret = drm_mode_group_init_legacy_group(dev,
  				&dev->primary->mode_group);
  		if (ret)
  			goto err_unload;
  	}
  
  	ret = 0;
  	goto out_unlock;
  
  err_unload:
  	if (dev->driver->unload)
  		dev->driver->unload(dev);
  err_minors:
  	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
  	drm_minor_unregister(dev, DRM_MINOR_RENDER);
  	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
  out_unlock:
  	mutex_unlock(&drm_global_mutex);
  	return ret;
  }
  EXPORT_SYMBOL(drm_dev_register);
  
  /**
   * drm_dev_unregister - Unregister DRM device
   * @dev: Device to unregister
   *
   * Unregister the DRM device from the system. This does the reverse of
   * drm_dev_register() but does not deallocate the device. The caller must call
   * drm_dev_unref() to drop their final reference.
   */
  void drm_dev_unregister(struct drm_device *dev)
  {
  	struct drm_map_list *r_list, *list_temp;
  
  	drm_lastclose(dev);
  
  	if (dev->driver->unload)
  		dev->driver->unload(dev);
  
  	if (dev->agp)
  		drm_pci_agp_destroy(dev);
  
  	drm_vblank_cleanup(dev);
  
  	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
  		drm_legacy_rmmap(dev, r_list->map);
  
  	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
  	drm_minor_unregister(dev, DRM_MINOR_RENDER);
  	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
  }
  EXPORT_SYMBOL(drm_dev_unregister);
  
  /**
   * drm_dev_set_unique - Set the unique name of a DRM device
   * @dev: device of which to set the unique name
   * @fmt: format string for unique name
   *
   * Sets the unique name of a DRM device using the specified format string and
   * a variable list of arguments. Drivers can use this at driver probe time if
   * the unique name of the devices they drive is static.
   *
   * Return: 0 on success or a negative error code on failure.
   */
  int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
  {
  	va_list ap;
  
  	kfree(dev->unique);
  
  	va_start(ap, fmt);
  	dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
  	va_end(ap);
  
  	return dev->unique ? 0 : -ENOMEM;
  }
  EXPORT_SYMBOL(drm_dev_set_unique);
  
  /*
   * DRM Core
   * The DRM core module initializes all global DRM objects and makes them
   * available to drivers. Once setup, drivers can probe their respective
   * devices.
   * Currently, core management includes:
   *  - The "DRM-Global" key/value database
   *  - Global ID management for connectors
   *  - DRM major number allocation
   *  - DRM minor management
   *  - DRM sysfs class
   *  - DRM debugfs root
   *
   * Furthermore, the DRM core provides dynamic char-dev lookups. For each
   * interface registered on a DRM device, you can request minor numbers from DRM
   * core. DRM core takes care of major-number management and char-dev
   * registration. A stub ->open() callback forwards any open() requests to the
   * registered minor.
   */
  
  static int drm_stub_open(struct inode *inode, struct file *filp)
  {
  	const struct file_operations *new_fops;
  	struct drm_minor *minor;
  	int err;
  
  	DRM_DEBUG("\n");
  
  	mutex_lock(&drm_global_mutex);
  	minor = drm_minor_acquire(iminor(inode));
  	if (IS_ERR(minor)) {
  		err = PTR_ERR(minor);
  		goto out_unlock;
  	}
  
  	new_fops = fops_get(minor->dev->driver->fops);
  	if (!new_fops) {
  		err = -ENODEV;
  		goto out_release;
  	}
  
  	replace_fops(filp, new_fops);
  	if (filp->f_op->open)
  		err = filp->f_op->open(inode, filp);
  	else
  		err = 0;
  
  out_release:
  	drm_minor_release(minor);
  out_unlock:
  	mutex_unlock(&drm_global_mutex);
  	return err;
  }
  
  static const struct file_operations drm_stub_fops = {
  	.owner = THIS_MODULE,
  	.open = drm_stub_open,
  	.llseek = noop_llseek,
  };
  
  static int __init drm_core_init(void)
  {
  	int ret = -ENOMEM;
  
  	drm_global_init();
  	drm_connector_ida_init();
  	idr_init(&drm_minors_idr);
  
  	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
  		goto err_p1;
  
  	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
  	if (IS_ERR(drm_class)) {
  		printk(KERN_ERR "DRM: Error creating drm class.\n");
  		ret = PTR_ERR(drm_class);
  		goto err_p2;
  	}
  
  	drm_debugfs_root = debugfs_create_dir("dri", NULL);
  	if (!drm_debugfs_root) {
  		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
  		ret = -1;
  		goto err_p3;
  	}
  
  	DRM_INFO("Initialized %s %d.%d.%d %s\n",
  		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
  	return 0;
  err_p3:
  	drm_sysfs_destroy();
  err_p2:
  	unregister_chrdev(DRM_MAJOR, "drm");
  
  	idr_destroy(&drm_minors_idr);
  err_p1:
  	return ret;
  }
  
  static void __exit drm_core_exit(void)
  {
  	debugfs_remove(drm_debugfs_root);
  	drm_sysfs_destroy();
  
  	unregister_chrdev(DRM_MAJOR, "drm");
  
  	drm_connector_ida_destroy();
  	idr_destroy(&drm_minors_idr);
  }
  
  module_init(drm_core_init);
  module_exit(drm_core_exit);
  